Deodorizing resin compositions and formed deodorizing articles

ABSTRACT

A deodorizing resin composition is composed of 99.9-50 parts by weight of a thermoplastic resin and 0.1-50 parts by weight of a deodorizing ingredient. The deodorizing ingredient is a white or substantially colorless deodorizing agent, which may preferably be composed of 10-90 parts by weight of a zinc compound and 90-10 parts by weight of an aliphatic polycarboxylic acid or a salt thereof, an aromatic polycarboxylic acid or a salt thereof, an acidic polymer or a salt thereof, or a sulfate of aluminum. A formed deodorizing article can be obtained by forming or molding the deodorizing resin composition into a desired shape. Formed articles of the deodorizing resin composition of this invention can have desired beautiful colors and are adapted to absorb offensive odors.

This is a division, of application Ser. No. 07/185,409, filed on Apr.25, 1988. Which is continuation of Ser No. 06/928,377 filed 11/10/86.

BACKGROUND OF THE INVENTION

1) Field of the Invention:

This invention relates to deodorizing resin compositions and formeddeodorizing articles, and more specifically to formed deodorizingarticles suitable especially for use in packaging or wrapping variousmalodorous articles and the like. The term "formed articles" as usedherein should be interpreted in a broad sense so that it embracestherein various formed articles such as films, sheets, molded articles,etc.

2) Description of the Prior Art:

Deodorizers have been being used widely against various offensive odorsources. In order to package various malodorous articles, plastic films,aluminum foils, metal containers, glass containers and the like which donot have air permeability are used primarily.

Packages making use of such conventional packaging or wrappingmaterials, which do not have air permeability, can prevent emission ofoffensive odors of contents. Their handling is however inconvenientbecause offensive odors filling the interiors of the packages come outat once when the packages are opened.

SUMMARY OF THE INVENTION

The present inventors have carried out an extensive investigation with aview toward providing a solution to such drawbacks of conventionaltechniques as mentioned above. As a result, it has been found that theycan be solved by the incorporation of certain specific materials in athermoplastic resin to be employed upon production of a formed articlesuch as plastic sheet or plastic container since the resulting formedarticle, for example, packaging material has excellent deodorizingcapacity, leading to completion of this invention.

In one aspect of this invention, there is thus provided a deodorizingresin composition comprising 99.9-50 parts by weight of a thermoplasticresin and 0.1-50 parts by weight of a deodorizing ingredient. Thedeodorizing ingredient is a white or substantially colorless deodorizingagent.

In another aspect of this invention, there is also provided a formeddeodorizing article obtained by forming the above-described deodorizingresin composition.

It has been known in the prior art to use a ferrous salt as adeodorizing ingredient of a deodorizer. When such a deodorizingingredient is used in a form kneaded in a thermoplastic resin or thelike the ferrous salt however undergoes discoloration due to the highprocessing temperature of the thermoplastic resin. Accordingly, thethermoplastic resin is tinged in a brown color and at the same time, itsdeodorizing effects are lowered. Moreover, the commercial values ofresin articles to be formed from such a resin will loweredsignificantly. When activated carbon is used on the other hand, thethermoplastic resin is tinged in a black color. Unlike such prior arttechniques, a white or substantially colorless zinc compound is employedin lieu of such a ferrous salt or activated carbon in the presentinvention. On addition, a white or substantially colorless aliphaticpolycarboxylic acid or the like is also used in combination with thezinc compound, so that even at high processing temperatures employedupon kneading such deodorizing agents into the thermoplastic resin, thedeodorizing agents do not lose their deodorizing effects and undergolittle discoloration into brown or black colors. It has also been foundthat the zinc compound and the aliphatic polycarboxylic acid or the likeexhibit synergistic deodorizing effects greater than the sum of theirrespective deodorizing effects. The deodorizing resin composition ofthis invention can therefore exhibit sufficient deodorizing effects notonly for offensive odor components of the amine type but also forsulfur-containing offensive odor components. In addition, the resultantthermoplastic resin composition is either white or substantiallycolorless, it can be colored into any desired hue with one or more othercolorants.

Formed articles of the deodorizing resin composition of this inventioncan therefore have desired beautiful colors. When packaging materials ofthis invention are used for the package of highly malodorous produces,products, articles or the like, for example, fish, processed fishproducts, various pickled or salted vegetables, various other foods andthe like, the packaging materials themselves absorb offensive odorsgiven off from them. It is hence possible to avoid emission of strongoffensive odors into the surrounding atmosphere when these packages areopened. For the same reasons, usefulness of packaging materialsaccording to this invention are not limited to foods but they areequally effective in packaging various domestic kitchen refuse, factoryrefuse and the like.

Besides such packaging materials, the deodorizing resin composition ofthis invention is also useful as formed deodorizing articles suitablefor use at places where unpleasant or offensive odors occur or remain,for example, as raw materials for granular deodorizers, deodorizing walldecorating or finishing materials, deodorizing fibers and textile andother formed deodorizing articles.

The above and other objects, features and advantages of this inventionwill become apparent from the following description and the appendedclaims.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The term "thermoplastic resin" as used herein includes, for example,synthetic or modified thermoplastic resins, for example, polyolefinresins such as polyethylene and polypropylene, polyvinyl chloride,vinylon, polystyrene, polyamides, polyesters, and cellulose acetate,which have conventionally been used in various formed articles, forexample, plastic films, plastic sheets, plastic containers, fibers, etc.All of these thermoplastic resins are readily available on the marketfor use in the present invention. These thermoplastic resins may be insolid forms or in the form of liquid such as paste.

The individual deodorizing agents useful in the practice of thisinvention are themselves all known compounds. As the zinc compound, anyone of various zinc compounds may be employed, for example, an inorganiczinc compound such as zinc oxide, zinc sulfate, zinc chloride, zincphosphate, zinc nitrate or zinc carbonate, or an organic zinc salt suchas zinc acetate, zinc oxalate, zinc citrate, zinc fumarate or zincformate, with zinc flower (zinc oxide) or zinc carbonate beingparticularly preferred.

Illustrative examples of the aliphatic polycarboxylic acid useful in thepractice of this invention may include di- and tri-carboxylic acids suchas oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,pimelic acid, fumaric acid, maleic acid, methylmaleic acid,methylfumaric acid, itaconic acid, citraconic acid, mesaconic acid,acetylenic acid, malic acid, methylmalic acid, citric acid, isocitricacid and tartaric acid as well as their salts. In the present invention,citric acid or fumaric acid or its salt is especially preferred.

The term "aromatic carboxylic acid or a salt thereof" as used hereinincludes, for example, phthalic acid, terephthalic acid, isophthalicacid, trimellitic acid, 1,2,3-benzenetricarboxylic acid,1,2,3-benzenetricarboxylic acid, pyromellitic acid,benzenehexacarboxylic acid, naphthalenedicarboxylic acid,naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid,diphenyltetracarboxylic acid and azobenzenetetracarboxylic acid, as wellas their anhydrides and salts. It is trimellitic acid or its salt thatis particularly preferred in the present invention.

The term "acidic polymer" as used herein means a polymer containingsulfonic groups, carboxylic groups, sulfuric ester groups, phosphoricester groups or phenolic hydroxyl groups in its molecule. It may, forexample, include the following polymers.

a) Polymers containing carboxylic groups: Polyesters with terminalcarboxyl groups, obtained by reacting polycarboxylic acids such ascitric acid, tartaric acid and phthalic acid and polyhydric alcoholssuch as ethylene glycol, 1.4-butanediol and diethylene glycol whileusing the acids in excess amounts; Acidic cellulose derivatives modifiedby various polycarboxylic acids; Homopolymers of vinyl ether estermonomers and the like of polycarboxylic acids, and random copolymers,block copolymers, graft copolymers and like of the vinyl ether estermonomers and and other general monomers; Homopolymers of monomers suchas acrylic acid and methacrylic acid and random copolymers, blockcopolymers, graft copolymers and like of the monomers and other generalmonomers; Homopolymers of α,β-unsaturated vinyl monomers such as maleicanhydride and itaconic acid, and random copolymers, block copolymers,graft copolymers and like of the vinyl monomers;

b) Polymers containing sulfonic groups: Cellulose derivatives such asethyl cellulose, hydrogenacetate hydrogensulfate phthalate, cellulosehydrogenacetate hydrogensulfate phthalate, ethyl cellulosehydrogensulfobenzoate, sulfonbenzyl cellulose acetate and ethylsulfoethyl cellulose acetate; Sulfonic acid modified polymers obtainedby modifying polyvinyl alcohol or vinyl alcohol copolymers with sulfonicacid compounds (for example, o-sulfobenzoic acid, sulfopropionic acid,sulfovaleric acid, sulfobenzaldehyde, sulfophthalic acid, etc.); and

c) Polymers containing hydroxyl groups: Homopolymers of other sulfonicacids or phenolic group containing monomers, and random copolymers,block copolymers, graft copolymers and like of the other sulfonic acidsor phenolic group containing monomers;

Besides, may also be mentioned acidic modified products obtained bymodifying various polymers with carboxyl carboxyl, sulfonic or phenolicgroup containing compounds.

Of these, carboxyl-containing polymers are particularly preferred.

The term "sulfate of aluminum" as used herein include aluminum sulfate[Al₂ (SO₄)₃ ] and potassium aluminum sulfate [KAl(SO₄)₃ ] with aluminumsulfate being especially preferred.

The principal feature of this invention reside in the use, as adeodorizing ingredient, of at least one compound selected from the groupconsisting of aliphatic polycarboxylic acids, aromatic carboxylic acids,acidic polymers and sulfates of aluminum in combination with theabove-described zinc compound.

It has been known in the prior art to use a ferrous salt or activatedcarbon as a deodorizing ingredient of a deodorizer. When the ferroussalt is used in a form kneaded in a thermoplastic resin or the like, theferrous salt however undergoes discoloration because the processingtemperature of the thermoplastic resin or the like is high. Hence, thethermoplastic resin or the like is tinged in a brown color and at thesame time, its deodorizing effects are lowered. It is also difficult toapply other colors. Moreover, the commercial values of resin articles tobe formed from such a resin will lowered significantly. When activatedcarbon is used in a form kneaded in a thermoplastic resin on the otherhand, the thermoplastic resin is tinged in a black color. It was alsoimpossible to apply other colors to the thermoplastic resin.

In the present invention, a white or substantially colorless zinccompound is employed in lieu of such a ferrous salt or activated carbon.In addition, at least one compound selected from the above-describedgroup is also used in combination with the zinc compound, so that evenat high processing temperatures employed upon kneading such deodorizingagents into the thermoplastic resin, the deodorizing agents do not losetheir deodorizing effects and undergo little discoloration into a browncolor and the thermoplastic resin is hence not tinged. It has also beenfound that the zinc compound and the aliphatic polycarboxylic acid orthe like exhibit synergistic deodorizing effects greater than the sum oftheir respective deodorizing effects. The deodorizing resin compositionof this invention can therefore exhibit sufficient deodorizing effectsnot only for offensive odor components of the amine type but also forsulfur-containing offensive odor components. In addition, the resultantthermoplastic resin composition is not tinged into a brown or blackcolor by the above deodorizing agents and it can therefore be tingedeasily into a desired color with one or more other colorants.

In the deodorizing ingredient composed of a zinc compound and analiphatic polycarboxylic acid or the like such as those described above,their proportions are also important. Supposing the total amount is 100parts by weight, the zinc compound is used in an amount of 10-90 partsby weight whereas the aliphatic polycarboxylic acid or the like isemployed in an amount of 90-10 parts by weight. Such a combination andmixing ratio can best achieve the objects of this invention.

The deodorizing resin composition of this invention requires theabove-mentioned combination of the components as essential components.Besides, various additives known conventionally for resins, for example,one or more of colorants, fillers, extender pigments, plasticizers,stabilizers, ultraviolet absorbents and the like may also beincorporated as needed.

The deodorizing resin composition of this invention can be obtained byeither simply mixing the above components or melting, kneading andgranulating the resultant mixture into pellets. In addition, thedeodorizing resin composition of this invention may also be in the formof a master batch which contains the deodorizing ingredient at a highconcentration (for example, 10≅50 wt. %), so that it may be extendedwith a plain thermoplastic resin prior to its use.

The deodorizing resin composition of this invention is useful for theproduction of the formed deodorizing article of this invention.

The formed deodorizing article of this invention is obtained by formingthe above-described deodorizing resin composition into any one ofvarious desired shapes, for example, for example, a wrapping material inthe form of a plastic film or sheet or in the form of a formed article,e.g., a container of a desired shape obtained by forming the deodorizingresin composition in accordance with any one of various forming ormolding methods.

Formation of such films, sheets, containers and the like can beconducted by conventionally-known inflation molding machines, presses,calenders, extrusion molding machines, spinning machines, blow moldingmachines, injection molding machines, vacuum molding machines and thelike under various conventional conditions without need of theirmodifications. Formed deodorizing articles according this invention canhence be obtained with ease.

This invention will hereinafter be described more specifically by thefollowing Examples, in which all designations of "part or parts" and "%"mean part or parts by weight and wt. % unless otherwise specificallyindicated.

EXAMPLE 1

To 99 parts of low-density polyethylene, 1 part of a 10:3 mixture byweight of zinc carbonate and fumaric acid was added. They were mixed ina mixer and then kneaded in a 40 mm extruder (L/D: 28, C.R.: 3.1,Dulmage screw, cylinder temperature: 130° C., screw revolution speed: 70rpm), thereby a pellet-like deodorizing resin composition of thisinvention was obtained.

The above deodorizing resin composition was then charged in an inflationmolding machine (30 mm extruder, inner diameter of inflation die: 50 mm,cylinder temperature: 140° C., screw revolution speed: 60 rpm) to obtaina polyethylene film having a thickness of about 50 μm. The deodorizingperformance of the deodorizing sheet was tested. The following resultswere obtained.

Deodorizing test on ammonia

The above deodorizing sheet were cut into 50 mm×200 mm sheets. One ofthe thus-cut sheets was then suspended in a 300-ml Erlenmeyer flask,followed by an addition of 100 ml of 42 ppm aqueous ammonia. The outletof the flask was sealed with paraffin and the aqueous ammonia wasallowed to gasify fully. The flask was thereafter stored at 25° C. andupon an elapse of a predetermined time period, the concentration (ppm)of ammonia in the flask was measured by a Kitagawa's probe. Thefollowing results were obtained.

    ______________________________________                                                  Lapsed Time                                                                   1 day      2 days  9 days                                           ______________________________________                                        Blank       25           25      25                                           Invention   20           15      10                                           product                                                                       Comparative 20           18      15                                           Example                                                                       ______________________________________                                    

Deodorizing test on hydrogen sulfide

One of the above-cut sheets was placed in a 300-ml Erlenmeyer flask,followed by addition of 1 ml of an 800 ppm solution of sodium sulfide inwater and 0.1 ml of 1N sulfuric acid. The outlet of the flask was sealedwith paraffin and the resulting hydrogen sulfide was allowed to gasifyfully. The flask was thereafter stored at 25° C. and upon an elapse of apredetermined time period, the concentration (ppm) of hydrogen sulfidein the flask was measured by a Kitagawa's probe. The following resultswere obtained.

    ______________________________________                                                  Lapsed Time                                                                   1 day      2 days  9 days                                           ______________________________________                                        Blank       155          155     155                                          Invention   40           3       trace                                        product                                                                       Comparative 55           5        1                                           Example                                                                       ______________________________________                                    

EXAMPLES 2-18

Plastic wrapping films of this invention were separately obtained in thesame manner as in Example 1 except that the following ingredients wereused. Following the procedure of Example 1, their performance wasmeasured. Results are given below.

    ______________________________________                                        Example 2:                                                                    High-density polyethylene                                                                        95 parts                                                   8:2 Mixture of zinc oxide and                                                                     5 parts                                                   fumaric acid                                                                  ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       10                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 3:                                                                    Polypropylene      95 parts                                                   5:5 Mixture of zinc carbonate                                                                     5 parts                                                   and citric acid                                                               ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          16       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  25          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 4:                                                                    Polystyrene        98 parts                                                   3:7 Mixture of zinc chloride                                                                      2 parts                                                   and fumaric acid                                                              ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  17          13        7                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      55          55       55                                            Invention  40           3       trace                                         product                                                                       Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 5:                                                                    High-density polyethylene                                                                        99 parts                                                   10:3 Mixture of zinc carbonate                                                                    5 parts                                                   and trimellitic acid                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30           1       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 6:                                                                    High-density polyethylene                                                                        95 parts                                                   8:2 Mixture of zinc oxide                                                                         5 parts                                                   and trimellitic acid                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       11                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30          not      not                                           product                detected detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 7:                                                                    Polypropylene      95 parts                                                   5:5 Mixture of zinc carbonate                                                                     5 parts                                                   and trimellitic acid                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          16       11                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  40           3       trace                                         product                                                                       Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 8:                                                                    Polystyrene        98 parts                                                   3:7 Mixture of zinc chloride                                                                      2 parts                                                   and trimellitic acid                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  17          13       11                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  45           3       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 9:                                                                    High-density polyethylene                                                                        99 parts                                                   10:3 Mixture of zinc carbonate                                                                    1 parts                                                   and an acidic polymer ("NEW                                                   FRONTIER MI-400P",                                                            trade name; product of                                                        Dai-ichi Kogyo Seiyaku                                                        Co., Ltd., Kyoto, Japan)                                                      ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 10:                                                                   High-density polyethylene                                                                        95 parts                                                   8:2 Mixture of zinc oxide and                                                                     5 parts                                                   an acidic polymer ("TESKYD                                                    MRM43", trade name; product                                                   of Hitachi Kasei Polymer Co.,                                                 Ltd., Tokyo, Japan).                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       13                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 11:                                                                   Polypropylene      95 parts                                                   5:5 Mixture of zinc carbonate                                                                     5 parts                                                   and an acidic polymer                                                         ("TESKYD MRA-L", trade                                                        name; product of Hitachi                                                      Kasei Polymer Co., Ltd.,                                                      Tokyo, Japan).                                                                ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          16       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  25          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 12:                                                                   Polystyrene        98 parts                                                   3:7 Mixture of ferrous sulfide                                                                    2 parts                                                   and an acidic polymer ("NEW                                                   FRONTIER MI-400P",                                                            trade name; product of                                                        Dai-ichi Kogyo Seiyaku                                                        Co., Ltd., Kyoto, Japan)                                                      ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  17          13       10                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      55          55       55                                            Invention  40           3       trace                                         product                                                                       Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 13:                                                                   High-density polyethylene                                                                        95 parts                                                   8:2 Mixture of aluminum                                                                           5 parts                                                   sulfate and an acidic polymer                                                 ("TESKYD MRM43",                                                              trade name; product of Hitachi                                                Kasei Polymer Co., Ltd.,                                                      Tokyo, Japan).                                                                ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25        25                                           Invention  20          15       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 14:                                                                   Polyethylene       95 parts                                                   5:3:2 Mixture of zinc                                                                             5 parts                                                   carbonate, aluminum sulfate                                                   and an acidic polymer                                                         ("TESKYD MRA-L",                                                              trade name; product of Hitachi                                                Kasei Polymer Co., Ltd.,                                                      Tokyo, Japan)                                                                 ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          16       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  25          trace    not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 15:                                                                   High-density polyethylene                                                                        99 parts                                                   10:3 Mixture of zinc carbonate                                                                    1 parts                                                   and aluminum sulfate                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       11                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30           1       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 16:                                                                   High-density polyethylene                                                                        95 parts                                                   8:2 Mixture of zinc oxide and                                                                     5 parts                                                   aluminum sulfate                                                              ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  20          15       12                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  25           1       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 17:                                                                   Polyethylene       95 parts                                                   5:5 Mixture of zinc carbonate                                                                     5 parts                                                   and potassium aluminum sulfate                                                ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  18          13       10                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  35           2       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                        Example 18:                                                                   Polystyrene        98 parts                                                   3:7 Mixture of zinc chloride                                                                      2 parts                                                   and aluminum sulfate                                                          ______________________________________                                                 Lapsed time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      25          25       25                                            Invention  17          13       10                                            product                                                                       Comparative                                                                              20          18       15                                            Example                                                                       Deodorizing test on hydrogen sulfide:                                         Blank      155         155      155                                           Invention  30           1       not                                           product                         detected                                      Comparative                                                                              55           5        1                                            Example                                                                       ______________________________________                                    

In each of the above Examples 1-18, a film free of any deodorizingingredient was used as the blank while a film making use of ferroussulfate alone was employed in the Comparative Example.

Furthermore, the comparative products were all stained in brown colorswhile those produced respectively from the invention products were notstained practically.

In addition, bags were produced respectively from the films employed asthe blanks, invention products and comparative products in Examples1-18. Thawed small fish was placed within the bags. The bags were leftover and were then opened three days later. Little offensive odors werefelt in the bags produced from the films of this invention, whereasstrong offensive odors were emitted from the bags made of the blanks.Furthermore, the comparative products were all stained deeply in browncolors while those produced respectively from the invention productswere not stained practically.

EXAMPLE 19

Added to 80 parts of high-density polyethylene were 20 parts of a 10:4mixture by weight of zinc oxide and fumaric acid. The procedure ofExample 1 was then followed to obtain a deodorizing resin composition ofthis invention which contained the deodorizing ingredient at aconcentration of 20%.

The deodorizing resin composition was extended with plain high-densitypolyethylene to a total volume 20 times the original The resulting resincomposition was then molded into a bottle-like molded article having awall thickness of 1 mm, a diameter of 60 mm and a height of 170 mm bymeans of a blow molding machine (45 mm screw, screw revolution speed: 30rpm, cylinder temperature: 200° C.). Partially tainted meat washermetically sealed within the molded article. After allowing the moldedarticle to stand for 3 days, the offensive odor was remarkably weakercompared with that emitted from a molded article similar to the abovemolded article except for the exclusion of the deodorizing ingredient.

The following deodorizing ingredients were used instead of theabove-described deodorizing ingredients. Similar results were obtained.

(1) A 10:4 mixture by weight of zinc oxide and trimellitic anhydride.

(2) A 10:4 mixture by weight of zinc oxide and an acidic polymer ("NEWFRONTIER MI-400P", trade name; product of Dai-ichi Kogyo Seiyaku Co.,Ltd., Kyoto, Japan)

(3) A 10:4 mixture by weight of zinc oxide and potassium aluminumsulfate.

EXAMPLE 20

Seventy parts of polypropylene and 30 parts of a deodorizing ingredient(a 10:3 mixture of zinc acetate and fumaric acid) were mixed together.They were mixed for 2 minutes at 1,500 rpm in a Henschel mixer and thenkneaded in a 40-mm extruder (L/D: 28; C.R: 3.1; Dulmage screw; cylindertemperature: 200-215° C.; screw revolution speed: 90 rpm), therebyobtaining pellet-like deodorizing resin composition of this invention.It was extended to a natural resin to a total volume 10 times itsoriginal volume. The thus-extended resin was spun at 200-215° C. througha spinning machine, followed by stretching at a draw ratio of 3 intofibers of 15 denier. The deodorizing performance of the deodorizingfibers was tested. The following results were obtained.

Deodorizing test on ammonia

One gram of the above deodorizing fibers was placed in a 300-mlErlenmeyer flask, followed by an addition of 10 μl of 28% aqueousammonia. The outlet of the flask was sealed with paraffin and theaqueous ammonia was allowed to gasify fully. The flask was thereafterstored at 25° C. and upon an elapse of a predetermined time period, theconcentration (ppm) of ammonia in the flask was measured by a Kitagawa'sprobe. The following results were obtained.

    ______________________________________                                                 Lapsed time                                                                   5 minutes 30 minutes                                                                              120 minutes                                      ______________________________________                                        Blank      4000        4000      4000                                         Invention  2500         850      300                                          product                                                                       Comparative                                                                              3000        1000      500                                          Example                                                                       ______________________________________                                    

Deodorizing test on hydrogen sulfide

One gram of the above deodorizing fibers was placed in a 300-mlErlenmeyer flask, followed by addition of 1 ml of an 800 ppm solution ofsodium sulfide in water and 0.1 ml of 1N sulfuric acid. The outlet ofthe flask was sealed with paraffin and the resulting hydrogen sulfidewas allowed to gasify fully. The flask was thereafter stored at 25° C.and upon an elapse of a predetermined time period, the concentration(ppm) of hydrogen sulfide in the flask was measured by a Kitagawa'sprobe. The following results were obtained.

    ______________________________________                                                 Lapsed Time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Blank      170         170      170                                           Invention  trace       not      not                                           product                detected detected                                      Comparative                                                                               55          3        1                                            Example                                                                       ______________________________________                                    

The above procedure was repeated except for the use of the followingdeodorizing ingredients instead of the above-described deodorizingingredient. The following results were obtained.

(1) A 10:3 mixture by weight of zinc acetate and anhydrous sodiumtrimellitate.

    ______________________________________                                                 Lapsed time                                                                   5 minutes 30 minutes                                                                              120 minutes                                      ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      4000        4000      4000                                         Invention  2500         900      400                                          product                                                                       Comparative                                                                              3000        1000      500                                          Example                                                                       ______________________________________                                    

    ______________________________________                                                 Lapsed Time                                                                   1 day     2 days   9 days                                            ______________________________________                                        Deodorizing test on hydrogen sulfide:                                         Blank      170         170      170                                           Invention  trace       not      not                                           product                detected detected                                      Comparative                                                                               55          3        1                                            Example                                                                       ______________________________________                                    

(2) A 10:3 mixture by weight of zinc oxide and an acidic polymer("TESKYD MRA-L", trade name; product of Hitachi Kasei Polymer Co., Ltd.,Tokyo, Japan)

    ______________________________________                                                 Lapsed time                                                                   5 minutes 30 minutes                                                                              120 minutes                                      ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      4000        4000      4000                                         Invention  2500         850      300                                          product                                                                       Comparative                                                                              3000        1000      500                                          Example                                                                       ______________________________________                                                 Lapsed time                                                                   1 day     2 days    9 days                                           ______________________________________                                        Deodorizing test on hydrogen sulfide:                                         Blank      170         170       170                                          Invention  trace       not       not                                          product                detected  detected                                     Comparative                                                                               5           3         1                                           Example                                                                       ______________________________________                                    

(3) A 10:3 mixture by weight of zinc acetate and potassium aluminumsulfate.

    ______________________________________                                                 Lapsed time                                                                   5 minutes 30 minutes                                                                              120 minutes                                      ______________________________________                                        Deodorizing test on ammonia:                                                  Blank      4000        4000      4000                                         Invention  2500         850      400                                          product                                                                       Comparative                                                                              3000        1000      500                                          Example                                                                       ______________________________________                                                 Lapsed time                                                                   1 day     2 days    9 days                                           ______________________________________                                        Deodorizing test on hydrogen sulfide:                                         Blank      170         170       170                                          Invention  trace       not       not                                          product                detected  detected                                     Comparative                                                                               5           3         1                                           Example                                                                       ______________________________________                                         Note:                                                                         In each of the above tests, the blank was fibers not added with any           deodorizing ingredient, while ferrous sulfate was used solely in the          Comparative Example. The films of the Comparative Examples were stained i     brown colors while the invention products were not stained practically.  

EXAMPLE 21

Thoroughly mixed into a plastisol were 50 parts of a PVC paste resin("SUMILIT PXN", trade name; product of Sumitomo Chemical Co., Ltd.,Osaka, Japan), 20 parts of dioctyl phthalate, 4 parts of a plasticizerof the lactic acid ester type ("C.L.P.", trade name; product of DaihachiChemical Industry Co., Ltd., Osaka, Japan), 1 part of cadmium-bariumbase stabilizer, 20 parts of calcium carbonate, 5 parts of zinc oxide,and 20 parts of a mixture which consisted of 20 parts by weight ofpotassium aluminum sulfate, 15 parts by weight of citric acid and 5parts by weight of sodium citrate. The plastisol was then coated on oneside of a flame-retarded paper sheet to a thickness of 0.2 mm, followedby its gelation at 140° C. for 60 seconds. The thus-coated surface wasthereafter printed and embossed to provide a deodorizing PVC sheetmaterial of this invention.

The above deodorizing PVC sheet material of this invention was then cutinto 50 mm×200 mm sheets. Two sheets were then adhered with theiruncoated surfaces inside so as to avoid influence of the uncoatedsurfaces. The thus-adhered sheets were placed in a 300-ml Erlenmeyerflask, followed by an addition of 10 μl of 28% aqueous ammonia. Theflask was hermetically sealed to gasify the ammonia fully. At 25° C.,ammonia gas was detected periodically by means of a Kitagawa's probe.The following deodorizing effects were obtained (unit: ppm).

    ______________________________________                                                 Lapsed time                                                                   5 minutes 30 minutes                                                                              120 minutes                                      ______________________________________                                        Blank      4000        4000      4000                                         Invention  2500         700       100                                         product                                                                       ______________________________________                                         Note:                                                                         The blank was the same PVC sheet material as the invention product except     for the exclusion of the deodorizing ingredient.                         

Having now fully described the invention, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit or scope of the inventionas set forth herein.

We claim:
 1. A deodorized resin composition, consisting of:99.5-50 partsby weight of a thermoplastic resin and 0.1-50 parts by weight of acombination of 10-90 parts by weight of a zinc compound and 90-10 partsby weight of an aromatic polycarboxylic acid or a salt thereof.
 2. Thedeodorizing resin composition as claimed in claim 1, wherein thearomatic polycarboxylic acid or the sale thereof is trimellitic acid ora salt thereof.
 3. A deodorized shaped resin article obtained by shapinga resin composition consisting of 99.5-50 parts by weight of athermoplastic resin and 0.1-50 parts by weight of a combination of 10-90parts by weight of a zinc compound and 90-10 parts by weight of anaromatic polycarboxyilc acid or a salt thereof.
 4. The formeddeodorizing article as claimed in claim 3, wherein the aromaticpolycarboxylic acid or the salt thereof is trimellitic acid or a saltthereof.